The compound 10-phenyl-10H-phenoxaphosphine having the structure: ##STR1## was first disclosed in the literature by F. G. Mann and I. T. Millar, J. Chem. Soc., 3746 (1953) and its biological importance was noted by I. Granoth, et al., Israel J. Chem., 6, 651 (1968).
A simplified, more rapid method for its synthesis was disclosed by I. Granoth, et al., J. Chem. Soc., Perkin Transactions II, Part 1, 697 (1972). That process for the production of 10-phenyl-10H-phenoxaphosphine, illustrated in F-owchart A, consists of reacting n-butyl lithium in a 90% hexane so-ution with diphenyl ether in a mixture of tetrahydrofuran and ether under a nitrogen atmosphere at reflux for 5 hours, then adding phenylphosphonous dichloride dropwise, stirring the mixture and then adding water dropwise. ##STR2## Distillation of the organic layer and crystallization from ethanol give the desired product. The yield obtainable by that method is only 17%, however, so that the process is economically disadvantageous where commercial quantities of the compound are required.